Light weight weapon operating system and cartridge feed

ABSTRACT

A firearm is provided with a weapon operating system for firing large cartridges. The firearm may be a shoulder-fired, multi-shot, semiautomatic grenade launcher for firing grenade cartridges. The grenade launcher includes a magazine with a receptacle that holds one or more cartridges, a barrel, and a receiver coupled between the magazine and the barrel. The receiver includes a lightweight weapon operating system. Springs may be provided between the receiver and the magazine to isolate the receiver and barrel from the mass of cartridges in the magazine and the mounting resistance. A vernier feed system is disclosed for disengaging stacked cartridges in a tubular magazine from one another. A lifter based cartridge feed system is disclosed for magazine round control and/or chambering. A dwell is disclosed for retarding the breech lever after it has applied power to the accelerator lever during opening.

CROSS-REFERENCE TO RELATED APPLICATONS

[0001] This application is a U.S. Patent Application based off andclaiming priority to U.S. Provisional Patent Application No. 60/227,761,filed Aug. 24, 2000 still pending, the contents of which are hereinincorporated by reference.

BACKGROUND OF INVENTION

[0002] The present invention relates generally to firearms, and moreparticularly to firearms for firing grenades and other largeprojectiles. Some grenades are chemical, dispensing tear gas or nauseagas. Other grenades eject flares for signaling, marking rounds withsmoke, phosphorous for lighting fires, and regular high explosivegrenades for anti-personnel and anti-armor purposes.

[0003] The United States Army adopted the 40 mm M79 grenade launcher inthe early 1960's to provide the infantryman with an effective area-firefragmentation weapon having a much greater range than possible with handthrown grenades. Despite its effectiveness, the M79 is a single shotweapon limited to a low rate of fire. This low fire rate of single shotweapons can be a serious handicap because the grenadier is effectivelydisarmed while reloading the grenade launcher, providing the enemy anopportunity to attack or maneuver before the grenadier can furtherengage him. A further disadvantage with the M79 is that the riflefirepower of the infantry unit is reduced by one rifle.

[0004] Experienced grenadiers often do not use the weapon sights toestablish a firing angle for the grenade launcher, but rather fire afirst round at an angle of elevation based on experience. The grenadierobserves the impact of this ranging round to make any requiredadjustment in the aim of the weapon at the target. Even though thistechnique is widely employed, it suffers from a disadvantage as employedwith a single shot grenade launcher. The grenadier must lower the weaponto reload. Without exercising considerable skill, the weapon cannot bereturned closely to its previous firing position to make the desiredaiming correction, thus reducing the accuracy of the next fired round.Even if the grenadier can bring the target area under accurate fire, thedelay between the ranging round and each succeeding round increases thetime available for the target to take cover.

[0005] In order to address some of the problems associated with singleshot weapons, the M203 grenade launcher attachment was developed for theM16 rifle. While the M16/M203 system provides the grenadier with riflefire power in addition to grenade launching capabilities, the accuracyand grenade firing rate is degraded as compared to the M79 grenadelauncher because of the increased weight and bulk of the combinationweapon. In addition, the effectiveness of the M16 rifle attached to thegrenade launcher is reduced.

[0006] Self powered weapon operating systems are commonly classifiedaccording to how energy is extracted from the propellant gases tooperate the weapon. These systems can be classified as gas systems,recoil systems, and various types of blowback systems. These systemsextract energy from the propellant gas and convert this gas into kineticenergy, which is imparted to the moving parts of the operating system.Weapon operating systems may also be classified according to therelationship of their primary and secondary masses. In gas, recoil andretarded blowback operating systems, most of the kinetic energy of thesystem is stored in a primary mass, typically called the bolt carrier oroperating rod. The kinetic energy of the primary mass provides theenergy for unlocking the secondary mass, which is typically called thebolt. After unlocking the secondary mass, the primary mass picks up thesecondary mass and the two masses continue to recoil as a unit. Straightblow back weapons utilize only a primary mass.

[0007] Gas operated systems for grenade launchers are ineffective due tothe internal ballistic characteristics of grenade cartridges. Grenadecartridges generate very low chamber pressure and a short pressurepulse. When coupled with the high expansion ratio of the cartridge,little gas pressure remains for operating the weapon.

[0008] Recoil operation of a shoulder fired grenade launcher presentsdifficulties because of the mount sensitivity of recoil operated systemsespecially since there is a low ratio of weapon mass to projectile massin grenade launchers. Straight blowback operation for shoulder firedgrenade launchers also presents difficulties because bolt recoilvelocities cannot be kept within manageable limits without employingunacceptably massive bolts for a shoulder fired weapon.

[0009] There are also disadvantages associated with conventionalretarded blowback operation of grenade launchers. The energy availablefor transfer to the operating mechanism in a retarded blowback operatingsystem, as in a recoil system, depends on limiting receiver movementduring firing, which is governed by the mounting resistance of theweapon. Grenade projectiles are relatively heavy when compared to theshoulder weapons in which they are fired; thus, grenade launchers aremore sensitive to mounting resistance than are service rifles andmachine guns. For example the M16 rifle weight to projectile weightratio is about 800:1, and the M60 machinegun weight to projectile weightratio is about 1000:1. In contrast, if a grenade launcher weighs 5pounds, then the weapon to projectile weight ratio for a standard 40 mmgrenade is about 13:1. This very low ratio associated with the grenadelauncher is not conducive to reliable functioning in a conventionalretarded blowback operating system. This is because the mountingresistance will vary greatly depending on whether the grenade launcheris held firmly against the shooter's body or away from the shooter'sbody, as well as the number of cartridges remaining in the magazine. Ifthe receiver moves too far, then the receiver absorbs too much energy,thus reducing the energy available for driving the operating mechanism.

[0010] Multiple shot semi-automatic grenade launchers also have problemsthat relate to the recoil springs of the weapon. Conventionalcompression springs in weapon operating systems are limited to about 40fps loading velocity; beyond which springs suffer from destructivespring surge. Therefore, the initial velocity of the bolt carrier mustnot exceed 40 fps.

[0011] A shoulder fired grenade launcher requires a relatively strongrecoil spring to reliably chamber cartridges since the weapon is firedat high elevation angles and since the masses of a conventional bolt andof grenade cartridges are relatively large. This results in anotherproblem associated with conventional box magazines relative to cartridgefeeding and chambering grenade cartridges. A long overtravel for thebolt behind the top cartridge in the magazine is necessary to provideadequate time for the magazine follower spring to lift the cartridgestack to position another cartridge for chambering by the bolt. Arelatively strong magazine follower spring must also be provided foradequate cartridge feeding. Additionally, a long chambering ramp isnecessary which requires a long bolt travel, in spite of the nextgrenade cartridge typically being positioned as close as possible to thebore axis. Increasing the strength of the magazine follower springcauses the next cartridge in the magazine to exert a greater frictionalor braking effect on the recoiling parts. Such compromises in the designof multiple shot grenade launchers using conventional magazines resultin marginal reliability in cartridge feeding.

[0012] The relatively large mass of a grenade cartridge createsadditional problems. An example of a multiple shot grenade launcher witha three chambered design is provided in U.S. Pat. No. 5,052,144. Thegrenade launcher of the '144 patent includes a sliding horizontalmagazine serving as a firing chamber that aligns each cartridge to befired with the barrel. Since this magazine is displaced off-axisrelative to the bore, the center of gravity of the magazine changes witheach shot, causing the grenade launcher to recoil about a differentcenter of gravity. The magazine described in the '144 patent thuscreates a different horizontal angle of departure for each shot relativeto the line of sight, thus altering the point of impact of eachprojectile in azimuth.

[0013] While there have been attempts in the prior art to providemultiple shot grenade launchers, the need for improvements remains.Since the early 1960's, continuing governmental and private industryattempts have failed to field any shoulder fired multiple shotsemi-automatic grenade launchers. One reason for this failure is thatgrenade cartridges are very difficult to feed from the weapon magazineto the chamber. Grenade cartridges are large in diameter, short, blunt,fragile and heavy. Grenade cartridges with their fragile projectileogives require special system design considerations in order to deliverthe cartridge to the weapon chamber with the projectile undamaged.

[0014] The ogives of grenade service projectiles and various grenadetraining projectiles are fragile because of the thin windshieldscovering their fuses. Dye marker practice rounds, that have thin andbrittle plastic ogives designed to break easily on impact, often breakwhen dropped on a hard surface. Conventional feed systems designed forhard and tough projectiles are not designed to protect projectiles fromdamage during feeding and chambering. Neither do conventional systemsisolate cartridges in the magazine or cartridges in the feed system fromthe jarring caused by the recoil of firing.

[0015] Large capacity grenade cartridge magazines used with experimentalshoulder fired grenade launchers are usually of the detachable box ordrum magazine types that are temporarily attached to the weapon. Whenempty, a detachable magazine is replaced with another loaded magazine.Placement of a large capacity magazine below the grenade launcherrenders the weapon very awkward for firing from the prone position.Conventional box or drum magazines on grenade launchers are also awkwardand uncomfortable when carrying on the march whether the magazines arein or out of the weapon.

[0016] Detachable grenade launcher magazines are notoriously bulkybecause of the geometry necessary to accommodate large cartridges in boxand drum type magazines. In addition to the space required for thecartridges themselves, space is also required for the magazine followerand follower spring, as well as for the magazine body itself. Detachablemagazines represent a substantial parasitic weight in the logisticssystem as well as in the ammunition burden of the soldier. Other typesof grenade launcher magazine designs such as those using endless chainsor belts are even more bulky for the number of cartridges carried. Suchbulky magazines are very awkward for the soldier when aboard vehiclesand for carrying into combat. Additionally, detachable magazines forgrenade launchers are expensive.

[0017] The present invention is directed towards meeting some or all ofthe needs mentioned above while addressing some or all of thedeficiencies discussed above.

SUMMARY OF THE INVENTION

[0018] The present invention is directed to, among other features, aweapon operating system that has application with grenade launchers andother devices for firing low pressure cartridges. The weapon operatingsystem of one form of the present invention includes a breech lever andan accelerator lever, that transfer the recoil forces to the primarymass, such as an operating slide. The levers are disconnected from theprimary mass as the primary mass recoils in the firearm. Thus thepresent invention does not require consideration of a secondary masspick-up in the weapon operating system design. The design of theoperating system mass requirement of the present invention may be basedsolely upon weapon cycling requirements since the ratio of the primarymass to secondary mass is not a design consideration. This permits alighter weapon operating system.

[0019] In another form of the present invention, there is provided aweapon operating system that uses the energy provided from firing lowpressure grenade cartridges. Low pressure grenade cartridges operate atvery low chamber pressure with a short pressure pulse even though therecoil pulse is substantial. The recoil force from firing the chamberedcartridge is transmitted to the weapon operating system. The weaponoperating system includes a breech pad in communication with thecartridge. The breech pad is connected to a breech lever. The breechlever contacts an accelerator lever, and moves the accelerator leverwhen the cartridge is fired. The accelerator lever drives an operatingslide provided with an extractor and a rammer. The extractor removes thespent cartridge from the chamber for ejection. The rammer picks up asecond cartridge at the rear of the recoil stroke and positions thesecond cartridge in the chamber. Since the operating system does notrequire a bolt or bolt carrier, the mass of the recoiling parts islowered significantly. Lower mass in the recoiling parts, in turn,increases the ratio of the mass of the weapon to the mass of therecoiling parts which inherently improves functional reliability.

[0020] In one form of the present invention, the breech lever is hingedoff the barrel axis and perpendicular to the barrel axis. Theaccelerator lever is also hinged off the barrel axis opposite the breechlever hinge and perpendicular to the barrel axis. When the cartridge isfired, the breech lever and accelerator lever are each pivoted abouttheir respective hinges and the breech lever and accelerator lever areswung away from the barrel axis and de-coupled from the operating slideduring the recoil cycle.

[0021] According to another form of the present invention, there isprovided a grenade launcher with a weapon operating system thataddresses one or more concerns relating to the mounting resistance ofthe grenade launcher. In contrast to rifles and machineguns, grenadeprojectiles are relatively heavy when compared to grenade launcherweight. The operating system of the present invention transmits therecoil force from firing the cartridge through two levers and into aprimary mass which is of relatively low mass as compared to overallweapon weight. In one specific embodiment, the empty weight of theweapon without the primary mass is about 4.25 lbs., and the primary massweighs about 0.75 lbs. Since the primary mass is the only recoiling partof the weapon, the weight ratio of the weapon less recoiling parts torecoiling parts is about 5.66:1. This ratio is higher than would befound in a grenade launcher that has a secondary mass coupled to andrecoiling along with the primary mass. The higher ratio of the presentinvention makes the grenade launcher less sensitive to changes in themounting resistance provided by the shooter and the weight of cartridgesin the magazine.

[0022] According to yet another feature of the present invention, thereis provided a grenade launcher with springs between the receiver and themagazine housing that isolate the receiver and barrel from solid bearingagainst the magazine housing and the mounting resistance of the shooter.When the weapon is solidly mounted against the shoulder of the shooterand a cartridge is fired, the springs compress to permit the barrel andreceiver group to recoil approximately as a free body relative to themagazine housing and the mounting resistance. If the grenade launcher isfired without mounting resistance, the entire weapon recoils as a freebody. The grenade launcher is less sensitive to the mass of thecartridges remaining in the magazine and the mounting resistanceprovided by the shooter since the receiver and barrel are isolated fromthe magazine and mounting resistance. While isolating the magazine usingthese springs decreases the effective mass ratio of weapon plusprojectile, the resultant mass ratio is effectively made more uniformbetween various mounting conditions.

[0023] According to another form of the present invention there isprovided a magazine for retaining a column of grenade cartridges. Eachcartridge of the column of cartridges has a nose and a tail, the taildefining a cartridge rim. The magazine has at least one interior surfacedefining a bore for retaining the column of cartridges. The interiorsurface extends along an axis between a front end and a rear end. Thecolumn of cartridges is stacked nose to tail substantially along theaxis so that the nose of each cartridge points toward the front end. Themagazine also has a magazine follower positioned at the rear end of themagazine for pushing the column of cartridges toward the front end. Themagazine further includes a vernier member having a plurality ofcartridge locators. The vernier member rides on a plurality of pins suchthat the vernier member is movable within the bore from a first positionto a second position. In the first position the plurality of cartridgelocators are disengaged from the column of cartridges. In the secondposition at least some of the cartridge locators engage the column ofcartridges and displace the cartridges so engaged from contacting oneanother.

[0024] According to yet another form of the present invention there isprovided a positive round control system for a grenade launcher. Thepositive round control system comprises a slide, cartridge carrier,carrier drive and drive pawl. The slide extends between a forward endand a back end. The slide has a recess substantially adjacent the rearend. The slide moves forward and back substantially along a bore axis ofthe grenade launcher. The cartridge carrier includes a lifter and atleast one cartridge locator for securing a cartridge. The carrier driveis pivotally connected to the cartridge carrier by a carrier pin. Thedrive pawl is pivotally connected to the carrier drive and engages therecess of the slide during at least a portion of forward motion of theslide along the bore axis. The cartridge carrier is pivotally connectedto a carrier link by a link pin so that the carrier drive and thecartridge carrier and the carrier link pivot around the link pin as afunctional unit as the slide moves forward and the recess of the slideengages the drive pawl. The functional unit aligns the cartridge securedby the cartridge carrier on the bore axis of the grenade launcher.Theseand other features, aspects, embodiments, and advantages, including thecartridge feed mechanism and the cartridge magazine of the weapon, willbe discussed further below.

BRIEF DESCRIPTION OF DRAWINGS

[0025]FIG. 1 is a side elevation view of a grenade launcher according tothe present invention.

[0026]FIG. 2 is a side plan view in partial section illustrating themechanism in battery with a cartridge in the chamber and ready to fire.

[0027]FIG. 3 is a side plan view in partial section illustrating theweapon fired, with the recoiling parts moving out of battery.

[0028]FIG. 4 is a partial side plan view in partial section, including aschematic, illustrating selected parts of the mechanism in the batteryposition.

[0029]FIG. 5 is a partial side plan view in partial section, including aschematic, illustrating selected parts of the mechanism moving out ofbattery after firing.

[0030]FIG. 6 is a partial side plan view in partial section illustratingselected parts with the breech fully open.

[0031]FIG. 7 is a plan view from the breech end of the weapon in partialsection illustrating selected parts with the breech fully closed.

[0032]FIG. 8 is a plan view from the breech end of the weapon in partialsection illustrating selected parts with the breech fully open.

[0033]FIG. 9 is a side view of the vernier member in its fully forwardposition.

[0034]FIG. 10 is a side view of the vernier member having been movedrearward from its fully forward position of FIG. 9 so that the cartridgelocators are in position against the bottom of the cartridges.

[0035]FIG. 11 is a side view of the vernier member having been movedsufficiently rearward for the rear cartridge locator to have contactedthe extraction rim of the rear cartridge.

[0036]FIG. 12 is a side view of the vernier member moved fully to therear.

[0037]FIG. 13 is a side view of the feed system with the operating slidefully rearward.

[0038]FIG. 14 is a side view of the feed system with the operating slidebeginning forward and rotating the cartridge carrier toward alignmentwith the barrel axis.

[0039]FIG. 15 is a side view of the feed system with the feed slidecontinuing forward having rotated the cartridge carrier with itscartridge into alignment with the bore axis.

[0040]FIG. 16 is a side view of the feed system having stopped rotating,having completed its work in feeding with the operating slide disengagedfrom the cartridge carrier and with the operating slide continuing tomove forward to chamber the cartridge.

[0041]FIG. 17 is a side view of the feed system remaining stopped, withthe operating slide continuing to move forward in chambering thecartridge.

[0042]FIG. 18 is a side view of the operating slide moving rearwardafter firing and coming into contact with the cartridge carrier.

[0043]FIG. 19 is a side view of the operating slide continuing towardits rearward position returning the cartridge carrier toward its initialposition.

[0044]FIG. 20A is a side view of selected parts with the carrier in itsinitial position, FIGS. 20B and 20C are the same as FIG. 20A butillustrated in rear and top views.

[0045] FIGS. 21A-C are the same as FIGS. 20A-C except the cartridge hasbeen rotated approximately 45 degrees toward the fully fed position.

[0046]FIGS. 22A and 22B illustrate the same parts as FIGS. 21A and 21Cwith the cartridge rotated to its fully fed position.

[0047] FIGS. 23A-C are side, rear and top views illustrating thefunction of selected parts during the recoil stroke of the mechanism.

[0048]FIGS. 24A and 24B are side and rear views illustrating how theprojectiles are isolated from each other and from the weapon magazine.

[0049]FIG. 25 is a plan view of one aspect of the operating system priorto and at the instant of firing.

[0050]FIG. 26 is a plan view of FIG. 25 at the time in the cycle inwhich the accelerator lever is transmitting force through theaccelerator lever to the operating slide.

[0051]FIG. 27 is a plan view of FIG. 25 at the time in the cycle inwhich the dwell is retarding the breech lever but the accelerator leveris continuing to rotate.

[0052]FIG. 28 is a plan view of FIG. 25 at the time in the cycle inwhich the operating slide continues rearward and rotates the breechlever and accelerator lever away from the axis of the bore.

[0053]FIG. 29 is a plan view of FIG. 25 at the time in the cycle laterthan that of FIG. 28 in which the operating slide continues rearward androtates the breech lever and accelerator lever further away from theaxis of the bore.

[0054]FIG. 30 is a plan view of FIG. 25 at the time in the cycle laterthan that of FIG. 29 in which the operating slide continues rearward andcontinues to rotate the breech lever away from the axis of the bore.

[0055]FIG. 31 is a plan view of FIG. 25 at the time in the cycle laterthan that of FIG. 30 in which the breech lever and accelerator leverhave been rotated completely away from the axis of the bore.

[0056]FIG. 31 is a plan view of one aspect of the operating system priorto and at the instant of firing.

[0057]FIG. 32 is a plan view of FIG. 31 at the time in the cycle inwhich the breech lever is transmitting force to the operating slide.

[0058]FIG. 33 is a plan view of FIG. 31 at the time in the cycle inwhich the operating slide continues rearward and rotates the breechlever away from the axis of the bore.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0059] For the purposes of promoting an understanding of the principlesof the invention, reference will now be made to the embodimentsillustrated in the drawings and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the invention is thereby intended. Any such alterationsand further modifications in the illustrated device, and any suchfurther applications of the principles of the invention as illustratedtherein are contemplated as would normally occur to one skilled in theart to which the invention relates.

[0060] In FIG. 1, there is illustrated a shoulder fired, multi-shot,semi-automatic grenade launcher 1. Grenade launcher 1 includes a barrel110, a combination magazine and butt stock 90, and a receiver 80therebetween. A handgrip/trigger mechanism 5 is secured to receiver 80.The magazine 90 has an interior surface 90 a defining a bore 90 bextending between a front end 91 and a rear end 92. The bore 90 bretains a column of cartridges 70 stacked nose to tail. The magazine 90has a magazine follower 75 driven by a spring (not illustrated) to pushthe column of cartridges toward the receiver 80 adjacent the front end91. Grenade launcher 1 provides capabilities for high rates of fire ofgrenade rounds which increases the possible number of rounds fired perunit of time. Multi-shot grenade launcher 1 also provides asignificantly higher hit probability per round since the grenadier canmaintain the weapon's aim at the target while observing the fall of shotsince reloading after each shot is not required. This permits thegrenadier to concentrate on the target rather than reloading,facilitating any adjustments in aim that may be required. The grenadiercan also quickly select another target or blanket the original targetwith some or all of the remaining rounds, if desired.

[0061] Referring to FIG. 2, a cross-sectional view is taken throughreceiver 80. Cartridge 70 is supported in the chamber of barrel 110 bybreech pad 10. Breech pad 10 is mounted to breech lever 20 by breech padpivot 140. Breech lever 20 is mounted to receiver 80 by breech leverpivot 50. Accelerator lever 30 is mounted to receiver 80 by acceleratorpivot 60. As illustrated in FIG. 4, accelerator lever 30 includes anaccelerator lug 130. Operating slide 40 is in its battery position andresting against the accelerator lug 130, which cannot be seen in FIG. 2.Breech lever 20 is in contact with accelerator lever 30 at bearing point150. It is contemplated that operating slide 40 for a 40 mm grenadelauncher may have a weight similar to a bolt carrier or operating rod ofa typical military service rifle.

[0062] Referring now to FIG. 3, the cartridge has been fired by aconventional firing mechanism (not illustrated). Projectile 170 is beingdriven forward by the propellant gas, and the empty cartridge case 160is being driven rearward. The recoil force of firing is being applied bythe base of cartridge case 160 to breech pad 10 through breech pad pivot140 to breech lever 20, through bearing point 150, to accelerator lever30, through accelerator lug 130 to operating slide 40. Breech pad 10rotates on breech pad pivot 140 to maintain the face of breech pad 10flat against the base of cartridge case 160 as breech lever 20 rotates.Breech pad 10 transmits the recoil force to breech lever 20. Breechlever 20 is a third class lever with breech lever pivot 50 acting as thefulcrum. The force applied at breech pad pivot 140 applies work toaccelerator lever 30 through bearing point 150. The motion ofaccelerator lever 30 at bearing point 150 is faster but with less forcethan at breech pad pivot 140.

[0063] Accelerator lever 30 is also a third class lever with its fulcrumat accelerator pivot 60. The force applied to accelerator lever 30 atbearing point 150 rotates accelerator lever 30 about accelerator pivot60, with the work applied to operating slide 40 through the acceleratorlug 130 positioned in accelerator lug portion of cam path 180, asillustrated in FIGS. 4-6. Operating slide 40 is moving rearward at ahigher velocity than breech pad 10 by a factor determined by the ratiosof the lengths of the operating components of breech lever 20 andaccelerator lever 30, and governed by the mass of operating slide 40compared to the mass and velocity of projectile 170.

[0064] As illustrated in FIGS. 2-3, magazine/butt stock 90 is isolatedfrom direct bearing against receiver 80 by recoil modulator springs 120.Part of the recoil forces of firing are delivered to receiver 80 throughbreech lever pivot 50 and accelerator pivot 60 compressing recoilmodulator springs 120 against magazine/butt stock 90. The amount ofcompression of modulator springs 120 is governed by the inertialresistance of the mass of the magazine housing and its contents. Ifthere is no ammunition in magazine/butt stock 90, the resistance will beless and the modulator springs 120 will compress less than if a fullyloaded magazine is in magazine/butt stock 90.

[0065] Referring now to FIG. 4, the cartridge case and breech pad havebeen removed to illustrate more clearly the relationships of the breechlever 20, accelerator lever 30 and operating slide 40. The parts arefully in the battery position. Accelerator lug 130 of accelerator lever30, and breech lever lug 100 of breech lever 20 are engaged withoperating slide 40 in the vertical component of cam path 180.

[0066]FIG. 5, similar to FIG. 4, illustrates the point in the operatingcycle where firing has occurred and various components are being drivenin recoil. Breech lever 20 has been forced to rotate rearward bypropellant gas in the cartridge case (not illustrated), through thebreech pad, which has been removed for clarity. Accelerator lever 30 isbeing forced to rotate by breech lever 20. Accelerator lug 130 ofaccelerator lever 30 is in contact with operating slide 40 at theoperating slide contact 190, forcing the operating slide 40 to moverearward at a higher velocity than breech pad 10 by a factor determinedby the ratios of the lengths of the operating components of breech lever20 and accelerator lever 30, as governed by the mass of operating slide40 compared to the mass and velocity of projectile 170 (notillustrated).

[0067] Referring now to FIG. 6, operating slide 40 is illustrated ascontinuing to move in recoil. Breech lever lug 100 is positioned in thebreech lever portion of cam path 180 of operating slide 40, andaccelerator lug 130 is positioned in and follows the accelerator lugportion of cam path 180 of operating slide 40. Breech lever 20 andaccelerator lever 30 are rotated completely out of the path of the emptycartridge case (not illustrated) so the case may be fully extracted andejected. Breech lever 20 and accelerator lever 30 will remain completelyout of the path of the cartridge in the magazine until the nextcartridge is fully chambered. Further features relating to alternativeforms of the lugs and/or cam paths are discussed in greater detail belowwith respect to the dwell for retarding the breech lever illustrated anddescribed below with respect to FIGS. 25-31.

[0068] Referring now to FIG. 7, operating slide 40 is in its fullyforward position. Breech lever 20 and accelerator lever 30 are in thefull battery position as illustrated in FIGS. 2 and 4. Breech lever lug100 of breech lever 20 and accelerator lug 130 of accelerator lever 30are engaged with operating slide 40 in the vertical component of campath 180 of FIG. 6.

[0069] Referring now to FIG. 8, operating slide 40 is moving rearwardand breech lever 20 and accelerator lever 30 are in the fully openposition, as illustrated in FIG. 6. Breech lever lug 100 of breech lever20 and accelerator lug 130 of accelerator lever 30 are engaged withoperating slide 40 in their respective portions of cam path 180 of FIG.6. In this position, the breech is fully open for ejecting, and forchambering the next cartridge directly along the axis of the bore.

[0070] The projectile mass of a grenade cartridge is large compared tothe weapon mass, and grenade cartridges are relatively blunt, whichmakes round control difficult in conventional cartridge feeding systems.In one form of the present invention (see FIG. 1), the cartridges arecontained in a tubular magazine whose axis is preferably disposedexactly on the axis of the barrel. The next cartridge in the magazine isalready on the bore axis in its fully fed position directly behind thechamber when the cartridge in the chamber is fired. The “fully fed”position is defined as the cartridge positioned ready to be chambered.After firing, the breech lever and accelerator lever swing completelyout of the cartridge feed-way as the operating slide moves rearward inextraction and ejection. When the operating slide reaches its fullyrearward position, a rammer (not illustrated) of the operating slideengages the fully fed next cartridge. As the operating slide movesforward, the fresh cartridge is carried straight along the feed-way onthe bore axis and directly into the chamber.

[0071] One problem of stacking cartridges nose to tail in a magazine isthat the primer of the cartridge ahead is exposed to the front of theprojectile behind. The potential exists where a primer is exposed suchthat the trailing projectile may accidentally set off the primer ahead,especially during the jarring caused by firing of the cartridge in thechamber. Many center fire lever action rifles are designed with tubularmagazines that stack the cartridges nose to tail. The nose-to-tailproblem has been effectively been dealt with by providing theprojectiles with flat or round noses. Additionally, the projectile tendsto lie off center on the base of the cartridge ahead, not contacting theprimer ahead. But if the projectile behind happens to be centered on theprimer of the cartridge ahead, then the flatness or roundness of theprojectile behind causes any impact of the projectile with the primer tobe distributed such that the primer is not activated.

[0072] If the primer of a center fire rifle cartridge in a tubularmagazine were to be activated as the result of loading the magazine withcartridges having pointed projectiles, then the affected cartridge casewould rupture without generating the full cartridge pressure as whenfully supported in a locked chamber. This would still be a dangerousscenario, and likely injurious but not necessarily fatal to the shooter.Grenade cartridges, however, employ High/Low propellant systems whereinfull pressure is developed regardless of cartridge case support. Thus, agrenade cartridge that was accidentally fired in the magazine woulddevelop its full normal operating pressure. Therefore the cartridgecase, being substantially lighter than the projectile of the affectedcartridge, would be driven rearward at high velocity into the fuse ofthe projectile behind. In spite of the safety devices built into grenadefuses against pre-launch detonation, it is possible the warhead of theprojectile behind would be detonated. If one grenade in the magazinedetonated, it would likely sympathetically detonate the rest. The mostprobable result to the soldier with several grenade projectilesdetonating within inches of his/her head is apparent, and preferablyavoided.

[0073] Referring to FIGS. 9-12 there is illustrated one form of a“vernier” feed system of the present invention wherein the cartridgesare contained in a tubular magazine. Each of FIGS. 9-12 illustratesthree cartridges 70. It should be understood, however, that other feedsystems are contemplated as within the scope of the invention. Inparticular, a more preferred form of a feed system using a lifter isdescribed in greater detail below with respect to FIGS. 13-24.

[0074] The vernier magazine round control system is designed toalleviate the potential problem of magazine detonations in grenadelaunchers equipped with tubular magazines. The magazine is provided witha movable “vernier” member with cartridge locators that engage theextraction rims of the cartridges. The cartridge locators are separatedfrom each other by a distance greater than the length of the cartridgeso that when the vernier member is fully rearward, each cartridge primeris separated from the projectile behind the primer. In brief, when thevernier is fully forward it is completely disengaged from the cartridgesso the magazine follower can advance the stack. While not illustrated inFIGS. 9-12, means may be provided to prevent projectile-to-primercontact while advancing the stack, but this requires additional partsand added complexity. The vernier feed system is a round controlmechanism that takes a shorter stack of cartridges and stretches themout on a longer scale so they don't touch each other in the magazine.

[0075] With reference to FIGS. 9-12, it should be understood that thefront of the weapon from which the projectile is expelled is toward theright. Referring now to FIG. 9, vernier member 210 is in its fullyforward position being positioned on pins 220 carrying vernier 210 inslots 230. With vernier 210 in this position, cartridge locators 240 aredisengaged from the cartridges 70. The magazine follower (notillustrated) has pushed the cartridge column fully forward. Withreference to FIG. 10 vernier 210 has been moved rearward (by means notillustrated), and therefor upward riding on pins 220. Cartridge locators240 are in position against the bottoms of the cartridges 70 but not incontact with the cartridge rims 72.

[0076] Referring now to FIG. 11, vernier 210 has been moved sufficientlyrearward for rear cartridge locator 240 to have contacted the extractionrim 72 of the rear cartridge 70. The rear cartridge 70 is being movedtoward the rear. The other two cartridge locators 240 have not yetengaged with their respective cartridge rims 72. With reference to FIG.12, vernier 210 has been moved fully to the rear. All cartridge locators240 have contacted their respective cartridge case extraction rims 72.All cartridges 70 have been separated from each other. It should beunderstood that the mechanism involved may be designed to locate more orfewer cartridges as preferred.

[0077] The feed system described below and illustrated in FIGS. 13-24includes a lifter. The lifter feed system is the preferred embodimentbecause the lifter is simpler, eliminates the possibility of contact ofprimers with projectiles and permits much greater magazine capacitiesfor the same length of magazine or equal magazine capacity for a smallerlength magazine. This may be accomplished using a means for transferringperpendicularly disposed cartridges out of a magazine and into alignmentwith the weapon chamber. It should be understood that offset anglesother than perpendicular are contemplated as within the scope of theinvention. By employing positive round control the feed mechanismprevents all projectiles in the magazine and feed system from contactingeach other while in the weapon. Except for the possibility of lightcontact with cartridge locators during part of the recoil phase of theoperating cycle, the mechanism preferably prevents all projectiles fromcontact with any interior part of the weapon until the cartridge beingchambered is aligned with the axis of the weapon bore. From this pointthe cartridge is moved linearly forward into the chamber withoutrequiring ramping.

[0078] In one form of the present invention, the mechanism preferablyincludes a buffer that cushions the cartridges in the magazine and inthe feed system against the jarring of the weapon caused by firing.Additionally, it is preferable that at no time while the cartridge iswithin the weapon is the cartridge a free body depending upon its ownmomentum or any funneling effect or ramping to direct the movement ofthe cartridge. Even at ejection the empty cartridge case is physicallydisplaced clear of the weapon. Therefore, whether the weapon mechanismis cycled as in normal firing or if the weapon is slowly manuallycycled, then all round control functions are positively accomplishedwithout ever depending upon the momentum of the cartridge or emptycartridge case.

[0079] The weapon is preferably provided with an on-board magazine thatis single loaded or loaded from low cost, lightweight stripper clipsknown to those of ordinary skill in the art and used with numerousservice rifles since late in the 19th century. Stripper clips for thegrenade launcher may be designed to hold any required number ofcartridges. It is expected that a capacity of three to five rounds willprove to be optimal for grenade launcher stripper clips, depending uponthe diameter of the cartridges being used, and upon the magazinecapacity of the grenade launcher. It should be understood that othercapacity magazines are contemplated as within the scope of theinvention. Several strippers clips could be used to load the magazine.Stripper clips for the present invention are preferably inexpensive, ofno use to the enemy, and may be made of biodegradable material intendedto be discarded after use.

[0080] Since the weapon has an on-board magazine, there are no extramagazines with their duplication of springs, followers and magazinebodies that would otherwise be required for each magazine load ofammunition. This eliminates added bulk and weight from the soldier'sload. The on-board magazine may also be “topped off” with single rounds,or from stripper clips. Topping off is accomplished without opening theoperating mechanism or unloading the weapon. Thus the weapon may be keptready to fire at all times. Loose single rounds and/or loaded stripperclips may be carried in a shoulder bag as currently carried by thegrenadier for ready ammunition.

[0081] The on-board magazine in a weapon employing the preferredembodiment stores the cartridges in a row behind the feed mechanism withthe projectiles pointing substantially upward and with the stack ofcartridges extending toward the rear through the full length of the buttstock. This magazine arrangement results in the weapon having a sideprofile similar to that of the typical service rifle, except that thegrenade launcher does not have a magazine protruding below the weapon.When slung on the back or shoulder for carrying, this magazinearrangement permits the weapon to rest against the soldier's body in thesame manner as a conventional service rifle with no bulging magazine topress against the soldier. The on-board magazine is preferably loadedfrom the rear by opening the magazine door in the butt plate and theninserting single cartridges, or by placing a loaded stripper clip intoits slot and sliding the rounds out of the stripper clip and into themagazine. The stripper clip may then be discarded and the magazine doorclosed. Loading through the rear of the weapon permits the soldier tomaintain a low prone position while loading or reloading.

[0082] Referring to FIGS. 13-24, there is illustrated a cartridge feedsystem. The cartridge feed system of FIGS. 13-24 may transfer cartridgesfrom the perpendicular or otherwise offset plane of a magazine to thehorizontal plane of the barrel axis of a firearm. The cartridge feedsystem of FIGS. 13-24 preferably isolates projectiles from damage causedby contact with the firearm, or by contact with other cartridges in thefirearm.

[0083] With reference to FIGS. 13-24, it should be understood thatsprings and various other elements not required for understanding theinvention are not illustrated. Referring to FIG. 13, operating slide 350is in its fully rearward position with drive pawl 330 positioned readyto be picked up by recess 351 of operating slide 350 as it movesforward. Lifter 360 (not visible in FIG. 13 but illustrated in FIGS. 20and 21) has a notch 361 that is engaged with the cartridge extractionrim 362. Carrier drive 320, cartridge carrier 310 and carrier link 340couple with link pin 430 as a functional unit. Carrier drive 320 ispivotally connected to cartridge carrier 310 by carrier pin 420.Cartridge carrier 310 is pivotally connected to carrier link 340 by linkpin 430. Carrier link 340 pivots about stationary link pivot 400.

[0084] As is more clearly illustrated in FIG. 20B, the cartridgecontrollers 380 (also illustrated in FIGS. 20 and 21) are cammed out ofengagement with the cartridge by cartridge carrier 310. Cartridgelocators 390 (more clearly illustrated in FIGS. 20 and 21) are retainingthe cartridge within cartridge carrier 310. Referring now to FIG. 14,operating slide 350 is moving forward carrying drive pawl 330 andcarrier drive 320 forward. Cartridge carrier 310 is travelling in an arcas illustrated. Lifter 360, while not visible in FIGS. 13 and 14 islifting the cartridge as illustrated in FIG. 21. Cartridge controllers380 have returned to their initial position as illustrated in FIG. 23B.

[0085] With reference to FIG. 15, operating slide 350 has movedsufficiently forward to have caused cartridge carrier 310 to haverotated the axis of the cartridge onto the axis of the weapon bore.Drive pawl 330 has been cammed out of engagement with operating slide350 by stationary cam 370, thereby releasing cartridge carrier 310 frombeing rotated further. With the first cartridge having been removed fromthe magazine, the next cartridge in the magazine moves forward intoengagement with cartridge controllers 380. (See FIG. 23B for thepositions of cartridge controllers 380). The magazine follower andspring (not illustrated) have moved the stack of cartridges forward sothe front cartridge in the magazine has struck the cartridge stops 410.Cartridge stops 410 are spring loaded to serve as buffers to arrest theforward moving cartridges in the magazine. The spring loaded cartridgestops 410 also serve as buffers to cushion the cartridge stack from therecoil of firing. Isolating the cartridge stack from recoil also servesto maintain more uniform operating mechanism mounting resistance fromshot to shot regardless of how many rounds remain in the magazine.Uniform mounting resistance improves functional reliability andcontributes to better weapon accuracy. As illustrated in FIGS. 16 and17, operating slide 350, having disengaged from carrier drive 320continues to transport the cartridge toward the chamber.

[0086] Referring now to FIG. 18, the weapon has been fired and operatingslide 350 is moving rearward in its recoil stroke of the operatingcycle. Operating slide 350 has contacted receptacle 321 of carrier drive320 and carrier drive 320 is beginning to move rearward. The frontcartridge in the magazine is securely positioned by cartridgecontrollers 380 (as illustrated in FIGS. 23A-C) and cartridge stops 410and by the magazine follower or next round (not illustrated). Asillustrated in FIG. 19, operating slide 350 continues its rearwardstroke, rotating cartridge carrier 310 toward its initial position asillustrated in FIG. 13. Drive pawl 330 has rotated into its initialposition, thus when operating slide 350 begins its forward movement,carrier drive 320 will also move forward as in FIG. 14. Cartridgelocators 390, not illustrated in FIG. 19 (but illustrated in FIGS.23A-C) have contacted the cartridge and are being rotated by contactwith the cartridge in preparation for moving into their place to securethe cartridge as illustrated in FIGS. 21A-C.

[0087] Referring now to FIG. 20, selected parts are illustrated in side,rear and top views with the cartridge carrier (not illustrated in FIG.20) positioned as in FIG. 13. Cartridge locators 390 secure thecartridge from moving to the rear as illustrated in FIG. 20A. As bestillustrated in FIG. 20B, the lower projections of cartridge carrier 310have cammed cartridge controllers 380 out of engagement with thecartridge. FIGS. 21 A-C are similar to FIGS. 20A-C except that thecartridge carrier (not illustrated) has rotated the cartridgeapproximately 45 degrees toward the fed position illustrated in FIG. 14.Cartridge locators 390 and lifter 360 secure the cartridge within thecartridge carrier (not illustrated) so that the cartridge will bepositively transported into alignment with the weapon bore axis forchambering. Cartridge controllers 380 have returned to their initialposition, ready to secure the next cartridge the magazine presents.

[0088]FIG. 22 illustrates various components in the same positionillustrated in FIG. 15, except that certain components have been removedto more clearly illustrate the function of lifter 360. The cartridgecarrier (not illustrated) has rotated the cartridge to the fully fedposition. The front of lifter 360 has contacted stationary lifter cam440. Lifter cam 440 has rotated the front of lifter 360 upward and therear downward. Rotating the rear of lifter 360 downward has disengagednotch 361 of lifter 360 from the extraction rim 362 of the cartridge.The cartridge is now free to be transported into the chamber by therammer (not illustrated). Cartridge locators 390 will be rotated awayfrom the extraction rim of the cartridge by passage of the cartridgeextraction rim through cartridge locators 390. After passage of theextraction rim, cartridge locators 390 will return to their positionsillustrated in FIGS. 20 and 21. FIG. 23 illustrates various componentsat the same point in the cycle during which the cartridge carrier (notillustrated) is returning toward its initial position as illustrated inFIG. 19. Cartridge locators 390 are riding out over the ogive of thefront cartridge in the magazine. Lifter 360 is being rotated by contactwith the cartridge. When the cartridge carrier (not illustrated) returnsto the position illustrated in FIG. 13, cartridge locators 390 and notch361 of lifter 360 will engage the extraction rim of the front cartridgein the magazine as illustrated in FIG. 20 and cartridge controllers 380will have been disengaged as illustrated in FIG. 20B.

[0089] With reference to FIGS. 24A-B there are illustrated variousaspects of the retention of a cartridge within the magazine housing. Thelower part of the cartridge is guided by the narrow portion of magazinehousing 470 and by cartridge guide slot 460 that prevents the cartridgesfrom tipping and preventing the projectiles from touching each other.The rim of the cartridge is guided by cartridge guide slot 460 engagedwith the extraction rim of the cartridge. The gap between the projectileand magazine housing 450 is maintained because cartridge guide slot 460is engaged with the extraction rim of the cartridge preventing thecartridge from moving upward.

[0090] With reference to FIGS. 25-31 there is illustrated a dwellpreferably utilized with the operating system of FIGS. 1-8 for optimalfunctioning of the operating system. In order for the levers of theoperating system to return to battery (closed) position withoutclashing, it is preferable to briefly retard the breech lever after ithas applied power to the accelerator lever during opening. Retarding thebreech lever after the power impulse of firing causes the acceleratorlever to move away from the breech lever during opening. Using a dwellto retard the breech lever is not required on the opening stroke, but onthe closing stroke the clearance produced by the dwell is preferred toinsure the breech lever moves ahead of the accelerator lever in the samemanner as rotating spur gear teeth smoothly mesh. Without the dwell thebreech lever and accelerator lever may clash when closing in the samemanner as clashing spur gear teeth.

[0091] Referring now to FIG. 25 The cartridge case (not illustrated) ofa cartridge (not illustrated) being fired is pressing against breech pad510. Breech pad 510 is mounted on breech lever 520. Breech lever 520 isin contact with accelerator lever 530 at contact point 650. Drive lug630 of accelerator lever 530 is in contact with operating slide 540 atcontact point 580 (contact point 580 is more clearly illustrated in FIG.26 and most clearly illustrated in FIG. 27) in the upper portion of camgroove 560. Positioning lug 600 in groove 550 is subject to no forces atthis time, instead positioning lug 600 is merely riding in groove 550.At no time during the operating cycle are positioning lugs 600 and 610or grooves 550 and 590 subject to any more force than is required toproperly position breech lever 520 against its own inertia. Positioninglugs 600 and 610 are timed with grooves 550 and 590 for neutral contactuntil dwell 620 illustrated in FIG. 27 is reached.

[0092] The forces of firing are transmitted from breech pad 510 intobreech lever 520 that transmits the recoil force at contact point 650 toaccelerator lever 530 and through drive lug 630 of accelerator lever 530to operating slide 540 at contact point 580. Referring to FIG. 26, thecartridge case (not illustrated) is continuing to drive breech pad 510rearward which in turn causes breech lever 520 to pivot on its axis.Breech lever 520 contacts accelerator lever 530 at contact point 650 andforces accelerator lever 530 to rotate. Drive lug 630 of acceleratorlever 530 is in contact with and driving operating slide 540 at contactpoint 580. The mechanical disadvantage provided by breech lever 520 andaccelerator lever 530 causes operating slide 540 to move at severaltimes the speed of breech pad 510, thus retarding the opening of breechpad 510. This retardation is described above with respect to FIGS. 1-8.

[0093] Referring now to FIG. 27 in which the pressure in the firingchamber has subsided to zero after the projectile has exited the muzzle.Operating slide 540 continues rearward of its own momentum that wasimparted by firing. At this time operating slide 540 no longer providesresistance against opening of the mechanism, but instead operating slide540 now provides the energy for opening the mechanism. Positioning lug600 has entered the horizontally straight portion, or dwell 620, ofgroove 550. While positioning lug 600 is in dwell portion 620 of groove550 of operating slide 540, breech lever 520 does not rotate becausedwell portion 620 of groove 550 is parallel to the direction of travelof slide 540. It should be understood that a complete halt of therotation of breech lever 520 is not required, instead a slowing of therotation of breech lever 520 will be sufficient to generate a separationthat permits the breech lever 520 to close ahead of the acceleratorlever 530. But since drive lug 630 of accelerator lever 530 is incontact with operating slide 540 at contact point 580 in the verticalportion of groove 560, accelerator lever 530 continues to rotate whilebreech lever 520 does not rotate. This permits breech lever 520 andaccelerator lever 530 to separate from each other at contact point 650resulting in clearance 660. While this clearance is not required atopening of the mechanism, clearance is preferred at closing to permitbreech lever 520 to close ahead of accelerator lever 530. Withoutclearance between breech lever 520 and accelerator lever 530 at contactpoint 650 there may be clashing between breech lever 520 and acceleratorlever 530 instead of the smooth meshing at contact point 650 duringclosing.

[0094] Referring to FIGS. 28-31, operating slide 540 continues rearward.Positioning lug 600 riding in groove 550 rotates breech lever 520completely away from the axis of the bore as illustrated in FIG. 31.Accelerator lever 530 is also rotating away from the axis of the bore asillustrated in FIG. 31 by drive lug 630 riding in groove 560 ofoperating slide 540. Positioning 610 lug enters groove 590 in FIG. 29.The empty cartridge (not illustrated) will be ejected as operating slide540 moves rearward, and the rammer (not illustrated) attached tooperating slide 540 will engage a fresh cartridge that will be carriedforward and into the chamber on the closing stroke. The grooves andlevers will cause breech pad 510 to close behind the cartridge (notillustrated) in preparation for firing.

[0095] It should be understood that alternative forms of the recoiltransmitting mechanism are contemplated as within the scope of theinvention. For example, the form illustrated in FIGS. 1-8 and FIGS.25-31 includes two levers, a breech lever and an accelerator lever.While the use of a breech lever and an accelerator lever is preferredfor chambering grenade cartridges, it should be understood that the useof a single lever design, while less preferred, is contemplated aswithin the scope of the invention.

[0096] Referring now to FIGS. 32-34 there is illustrated a form of theinvention utilizing a single lever. A cartridge (not illustrated) issupported in the chamber of the barrel by breech pad 710. Breech pad 710is mounted to breech lever 720 by breech pad pivot 840. Breech lever 720is mounted to the receiver by breech lever pivot 850. The breech leverincludes a lug 800. Drive lug 800 of breech lever 720 is in contact withoperating slide 740 within the cam groove 750. Operating slide 740 is inits battery position and resting against the breech lever lug 800. It iscontemplated that operating slide 740 for a 40 mm grenade launcher mayhave a weight similar to a bolt carrier or operating rod of a typicalmilitary service rifle.

[0097] Referring now to FIG. 33, the cartridge has been fired by aconventional firing mechanism (not illustrated). A projectile (notillustrated) is being driven forward by the propellant gas, and theempty cartridge case (not illustrated) is being driven rearward. Therecoil force of firing is being applied by the base of the cartridgecase to breech pad 710 through breech pad pivot 840 to breech lever 720,through bearing lug 800, to operating slide 740. The breech pad 710rotates on breech pad pivot 840 to maintain the face of breech pad 710flat against the base of the cartridge case as breech lever 720 rotates.Breech pad 710 transmits the recoil force to breech lever 720. The forceapplied at breech pad pivot 840 applies work to operating slide 740through drive lug 800.

[0098] Referring now to FIG. 34, operating slide 740 continues rearwardof its own momentum that was imparted by firing. At this time operatingslide 740 no longer provides resistance against opening of themechanism, but instead operating slide 740 now provides the energy foropening the mechanism. Breech lever drive lug 800 has entered ahorizontally straight portion of groove 750. While lug 800 is in thehorizontally straight portion of groove 750 of operating slide 740,breech lever 720 does not rotate because the straight portion of groove750 is parallel to the direction of travel of slide 740.

[0099] In designing a weapon utilizing various aspects or the entiretyof the present invention the bolt assembly mass need not dictate thedesign. Instead, the design is driven by weapon cycling requirementssince there is no bolt in the operating system of grenade launcher 1.The operating slide must receive and store only enough energy for movingthe parts through the steps in the functioning cycle of the weapon. Themagazine follower spring provides some of the energy for chambering thecartridge. Since the breech is not strictly locked, and because gaspressure against the inside of the cartridge case initiates extraction,very little energy is required to complete extraction of the firedcartridge. Also, since the breech lever and accelerator lever arealready rotating toward their fully open positions as a result offiring, very little energy is therefore required of the operating slideto fully open the breech lever and accelerator lever. Ejection of theempty cartridge case requires only a minimal amount of energy in orderto move the empty cartridge off-axis and out of the weapon.

[0100] Chambering the cartridge requires the greatest amount of energy.A low velocity 40 mm grenade cartridge weighs about 0.5 pounds and, inone form of the present invention, preferably requires transfer linearlyforward into the chamber. The force of the magazine follower spring isof direct assistance in chambering, rather than being a frictionhindrance as previously discussed with respect to conventional boxmagazines. If the muzzle is elevated while firing, the low mass of therecoiling parts relative to the force of the drive spring cycles theweapon more reliably than if a conventional bolt/bolt carrier were usedbecause the recoiling parts of the invention are much lighter than inconventional systems.

[0101] While the invention has been illustrated and described in detailin the drawings and foregoing description, the same is to be consideredas illustrative and not restrictive in character, it being understoodthat only the preferred embodiment has been illustrated and describedand that all changes and modifications that come within the spirit ofthe invention are desired to be protected. For example, althoughreference has been made herein to grenade cartridges, the invention issuitable for use with other types of cartridges, such as tear gascartridges, smoke cartridges, shotgun cartridges, and the like. Inreading the claims it is intended that when words such as “a”, “an”, “atleast one”, “at least a portion” are used there is no intention to limitthe claim to only one item unless specifically stated to the contrary inthe claim. Further, when the language “at least a portion” and/or “aportion” is used the item may include a portion and/or the entire itemunless specifically stated to the contrary.

What is claimed is:
 1. A firearm for firing a cartridge, comprising: amagazine having a rearward end and a forward end, the magazine having areceptacle holding one or more cartridges therein; a barrel having arearward end and a forward end, the barrel having a bore with a centerbore axis extending therethrough; a receiver having a cavity extendingtherethrough in communication with the magazine receptacle and thebarrel bore such that the bore axis extends through the cavity, thecavity further having a chamber portion adjacent a rearward end of thebarrel bore to hold one of the cartridges in a firing position, thereceiver including a weapon operating system having: a slide extendingsubstantially parallel with the bore axis adjacent to the receivercavity; a recoil transmitting mechanism coupled to the receiver and incontact with the slide, the recoil transmitting mechanism incommunication with the cartridge when the cartridge is in the firingposition; and a trigger assembly operable to fire a chambered cartridge,wherein the fired cartridge causes the recoil transmitting mechanism todisplace the slide rearwardly.
 2. The firearm of claim 1, wherein therecoil transmitting mechanism includes: a breech lever in contact withthe cartridge, the breech lever pivotally coupled to the receiver at afirst location remote from the contact with the cartridge, the breechlever further including a breech lug engaging the slide when thecartridge is in the firing position; and an accelerator lever in contactwith the breech lever and pivotally coupled to the receiver at a secondlocation and in contact with the breech lever, the accelerator leverincluding an accelerator lug engaging the slide when the cartridge is inthe firing position.
 3. The firearm of claim 2, wherein the slideincludes a breech lever cam path and an accelerator cam path, the breechlug positioned in the breech cam lever path and the accelerator lugpositioned in the accelerator cam path.
 4. The firearm of claim 3,wherein the breech lever includes: a lever arm, the breech lug extendingfrom the lever arm into the breech lever cam path; a breech padpivotally coupled to the lever arm, the breech pad having a bearingsurface in contact with the cartridge.
 5. The firearm of claim 1,wherein the firearm is a grenade launcher and the cavity of the receiveris in communication with the magazine receptacle through a positiveround control system.
 6. The firearm of claim 5, the positive roundcontrol system comprising: the slide extending substantially parallelwith the bore axis adjacent to the receiver cavity, the slide having arecess substantially adjacent a rear end, the slide movable forward andback substantially along the bore axis; a cartridge carrier having alifter and at least one cartridge locator for securing a cartridge; acarrier drive pivotally connected to the cartridge carrier by a carrierpin; a drive pawl pivotally connected to the carrier drive, the drivepawl engaging the recess of the slide during at least a portion offorward motion of the slide along the bore axis; and, wherein thecartridge carrier is pivotally connected to a carrier link by a link pinso that the carrier drive and the cartridge carrier and the carrier linkpivot around the link pin as a functional unit as the slide movesforward and the recess of the slide engages the drive pawl, thefunctional unit aligning the cartridge secured by the cartridge carrieron the bore axis of the grenade launcher.
 7. The firearm of claim 6,wherein the magazine is an onboard magazine positioned behind thecartridge carrier, the receptacle of the onboard magazine storing aplurality of cartridges, each cartridge including a projectile pointingsubstantially perpendicular to the bore axis.
 8. The firearm of claim 1,wherein the magazine extends rearwardly from the receiver.
 9. Thefirearm of claim 8, wherein the magazine is substantially tubular. 10.The firearm of claim 8, wherein the magazine retains a column of grenadecartridges, each cartridge having a nose and a tail, the tail defining acartridge rim, the magazine comprising: at least one interior surfacedefining a bore for retaining the column of cartridges, the interiorsurface extending along an axis between a front end and a rear end, thecolumn of cartridges being stacked nose to tail substantially along theaxis so that the nose of each cartridge points toward the front end; amagazine follower positioned at the rear end of the magazine for pushingthe column of cartridges toward the front end; a vernier member having aplurality of cartridge locators, the vernier member riding on aplurality of pins such that the vernier member is movable within thebore from a first position wherein the plurality of cartridge locatorsare disengaged from the column of cartridges to a second positionwherein at least some of the cartridge locators engage the column ofcartridges and displace the cartridges so engaged from contacting oneanother.
 11. The firearm of claim 10, wherein the cartridge locators aredisengaged from the column of cartridges when the vernier member is inits fully forward position, and wherein the column of cartridges aresequentially separated beginning with the rearmost cartridge when thevernier member is advanced rearward.
 12. The firearm of claim 3, furtherincluding means for retarding the rotation of the breech lever away fromthe bore axis.
 13. The firearm of claim 12, wherein the means forretarding includes a dwell in the breech lever cam path.
 14. The firearmof claim 1, wherein the recoil transmitting mechanism includes: a singlelever in contact with the cartridge, the lever pivotally coupled to thereceiver at a first location remote from the contact with the cartridge,the lever further including a drive lug engaging a lever cam path in theslide when the cartridge is in the firing position.
 15. The firearm ofclaim 14, wherein the lever further includes a breech pad pivotallycoupled to the lever, the breech pad having a bearing surface in contactwith the cartridge.
 16. A firearm for firing a cartridge, comprising: amagazine having a rearward end and a forward end, the magazine having areceptacle holding one or more cartridges therein; a barrel having arearward end and a forward end, the barrel having a bore with a centerbore axis extending therethrough; a receiver having a cavity extendingtherethrough in communication with the magazine receptacle and thebarrel bore such that the bore axis extends through the cavity, thecavity further having a chamber portion adjacent a rearward end of thebarrel bore to hold one of the cartridges in a firing position, thereceiver including a weapon operating system having: a slide extendingsubstantially parallel with the bore axis adjacent to the receivercavity; a breech lever substantially adjacent to the cartridge when thecartridge is in the firing position, the breech lever pivotallyconnected to the receiver at a first location; and an accelerator leverin contact with the breech lever and coupled to the slide when thecartridge is in the firing position, the accelerator lever pivotallyconnected to the receiver at a second location substantially oppositethe first location; and a trigger assembly operable to fire thecartridge in the chamber, wherein the fired cartridge causes the breechlever to direct the accelerator lever against the slide to displace theslide rearwardly.
 17. The firearm of claim 16, wherein: the breech leverincludes a breech lug engaging the slide when the cartridge is in thefiring position; and the accelerator lever includes an accelerator lugengaging the slide when the cartridge is in the firing position.
 18. Thefirearm of claim 17, wherein the slide includes a breech lever cam pathand an accelerator cam path, the breech lug positioned in the breechlever cam path and the accelerator lug positioned in the accelerator campath.
 19. The firearm of claim 18, wherein the breech lever includes: alever arm, the breech lug extending from the lever arm into the breechlever cam path; and a breech pad pivotally coupled to the lever arm, thebreech pad having a bearing surface in contact with the cartridge. 20.The firearm of claim 19, further including means for retarding therotation of the breech lever away from the bore axis.
 21. The firearm ofclaim 20, wherein the means for retarding includes a dwell in the breechlever cam path.
 22. A firearm for firing a cartridge, comprising: abarrel having a rearward end and a forward end, the barrel having a borewith a center bore axis extending therethrough; a magazine having arearward end and a forward end, the magazine having a receptaclecentered about and holding one or more cartridges therein; and areceiver coupled to the rearward end of the barrel, the receiver furtherbeing coupled to the forward end of the magazine with at least onespring member therebetween.
 23. The firearm of claim 22, wherein thereceiver further includes a weapon operating system having: a chamberfor holding one of the cartridges in a firing position; a slide; and arecoil transmitting mechanism coupled to the receiver and in contactwith the slide, the recoil transmitting mechanism in communication withthe cartridge when the cartridge is in the firing position.
 24. Thefirearm of claim 1, wherein the recoil transmitting mechanism includes:a single lever in contact with the cartridge, the lever pivotallycoupled to the receiver at a first location remote from the contact withthe cartridge, the lever further including a drive lug engaging a levercam path in the slide when the cartridge is in the firing position. 25.The firearm of claim 14, wherein the lever further includes a breech padpivotally coupled to the lever, the breech pad having a bearing surfacein contact with the cartridge.
 26. A magazine for retaining a column ofgrenade cartridges, each cartridge having a nose and a tail, the taildefining a cartridge rim, comprising: at least one interior surfacedefining a bore for retaining the column of cartridges, the interiorsurface extending along an axis between a front end and a rear end, thecolumn of cartridges being stacked nose to tail substantially along theaxis so that the nose of each cartridge points toward the front end; amagazine follower positioned at the rear end of the magazine for pushingthe column of cartridges toward the front end; a vernier member having aplurality of cartridge locators, the vernier member riding on aplurality of pins such that the vernier member is movable within thebore from a first position wherein the plurality of cartridge locatorsare disengaged from the column of cartridges to a second positionwherein at least some of the cartridge locators engage the column ofcartridges and displace the cartridges so engaged from contacting oneanother.
 27. The magazine of claim 26, wherein each cartridge locator ofthe vernier member corresponds to one of the column of cartridges. 28.The magazine of claim 27, wherein each cartridge locator engaging thecolumn of cartridges engages the rim of the corresponding cartridge. 29.The magazine of claim 26, wherein the cartridge locators are disengagedfrom the column of cartridges when the vernier member is in its fullyforward position, and wherein the column of cartridges are sequentiallyseparated beginning with the rearmost cartridge when the vernier memberis advanced rearward.
 30. The magazine of claim 29, wherein the magazineis a substantially tubular magazine.
 31. A positive round control systemfor a grenade launcher, comprising: a slide extending between a forwardend and a back end, the slide having a recess substantially adjacent therear end, the slide movable forward and back substantially along a boreaxis of the grenade launcher; a cartridge carrier having a lifter and atleast one cartridge locator for securing a cartridge; a carrier drivepivotally connected to the cartridge carrier by a carrier pin; a drivepawl pivotally connected to the carrier drive, the drive pawl engagingthe recess of the slide during at least a portion of forward motion ofthe slide along the bore axis; and, wherein the cartridge carrier ispivotally connected to a carrier link by a link pin so that the carrierdrive and the cartridge carrier and the carrier link pivot around thelink pin as a functional unit as the slide moves forward and the recessof the slide engages the drive pawl, the functional unit aligning thecartridge secured by the cartridge carrier on the bore axis of thegrenade launcher.
 32. The system of claim 31, further including anonboard magazine positioned behind the cartridge carrier, the onboardmagazine storing a plurality of cartridges, each cartridge including aprojectile pointing substantially upward.
 33. The system of claim 32,wherein the onboard magazine includes a spring loaded cartridge stop.34. The system of claim 33, wherein the onboard magazine furtherincludes cartridge controllers for retaining the forwardmost cartridge,and wherein the cartridge controllers are cammed out of engagement withthe forwardmost cartridge by the cartridge carrier.
 35. The system ofclaim 32, wherein the onboard magazine further includes cartridgecontrollers for retaining the forwardmost cartridge.
 36. The system ofclaim 35, wherein the cartridge controllers are cammed out of engagementwith the forwardmost cartridge by the cartridge carrier.
 37. The systemof claim 31, further including a stationary cam for camming the drivepawl out of engagement with the recess of the slide, thereby releasingthe cartridge carrier from further rotation.
 38. The system of claim 31,wherein the lifter has a first end and a second end, the lifter having anotch near the second end of the lifter, the notch sized to engage anextraction rim of the cartridge.
 39. The system of claim 38, furtherincluding a stationary lifter cam for rotating the lifter to disengagethe notch of the lifter from the extraction rim of the cartridge. 40.The system of claim 31, wherein the back end of the slide engages areceptacle on the carrier drive as the slide moves back along the boreaxis.
 41. The system of claim 31, further including an onboard magazinepositioned behind the cartridge carrier, the onboard magazine storing aplurality of cartridges, each cartridge including a projectile pointingsubstantially upward, wherein the lifter has a first end and a secondend, the lifter having a notch sized to engage an extraction rim of thecartridge near the second end of the lifter, and wherein the back end ofthe slide engages a receptacle on the carrier drive as the slide movesback along the bore axis.